The first chapter is called "Twenty elliptic functions and their forty trig series",
and it's all downhill from there. The style is a bit like that of Charles Dodgson's
serious writing, earnest italicizations and all.

2Tuning, timbre, spectrum, scale, by William A Sethares.

Why some notes sound good together and some don't. The answer isn't quite
what it's commonly thought to be. See
Sethares's website
for some more information, including some very interesting bits of music.

3Told on the air: broadcast stories for children,
compiled by Geoffrey Dearmer.

A collection of short articles, mostly on scientific and engineering themes,
from "A.E.I. News", the monthly magazine of Allied Electrical Industries Ltd.
Published in 1944. The author was, on the whole, wise to remain anonymous.

5A Christmas Sermon and other essays, by Robert Louis Stephenson.

Just what it says. Actually rather good.

6Introduction to circle packing, by Kenneth Stephenson.

This is the field in which I did my PhD. I'm cited a couple of times. The book
contains some nice mathematics and some nice pictures.
Oded Schramm,
an absolutely first-rate mathematician who tragically died in September,
was a big name in this field before he moved onto other areas of
mathematics.

7Shape, by George Stiny.

Attempts to combine geometry, formal grammars, and aesthetics.
I think there's less to it than meets the eye, but maybe I'm
just not sophisticated enough.

8Said or Sung, by Austin Farrar.

A collection of sermons.

9Universality and the Liar, by Keith Simmons.

"An essay on truth and the diagonal argument". I've had this for years,
but either I never got round to reading it or I've now forgotten everything
about it.

10The house that Nino built, by Giovanni Guareschi.

(Actually, this isn't currently on my shelves; I lent it to someone else
years ago and haven't chased it up.) Guareschi is better known as the
author of the "Don Camillo" books.

I have things on my shelves that are even more deservedly obscure than (e.g.)
#1 above, but filling my list with them seemed like it would rather miss the point.
I am also not convinced that obscurity and unlikeliness-to-be-on-your-shelves
are at all the same thing.